1. Field of the Invention
The present invention pertains to a releasable ball-type closure arrangement for an auger type gravel pack assembly for controlling fluid flow through the gravel pack assembly and into the gravel pack and the adjacent producing formation.
2. Background
In the installation of certain types of gravel pack assemblies, it is important to control the flow of fluid from the well, through the gravel pack and into the adjacent earth formation which is to be produced. The flow of wellbore fluid into the formation through the gravel pack can adversely contaminate the gravel pack as well as the formation. At the same time a limited flow of fluid in the direction indicated may be desirable in certain instances.
The control over fluid flow through a gravel pack and into the adjacent earth formation is particularly important when installing so-called auger-type gravel pack assemblies. This type of assembly is described in detail in U.S. Pat. No. 5,036,920 issued Aug. 6, 1991 to H. M. Cornette et al. and assigned to the assignee of the present invention. Certain improvements in fluid loss control systems for gravel pack assemblies are also described in U.S. patent application Ser. No. 07/877,924 filed: May 4, 1992 entitled Method and Apparatus for Gravel pack Completions by H. M. Cornette, Michael Johnson and Robert K. Bethel and also assigned to the assignee of the present invention. Basically, control over fluid flow through the gravel pack and into the formation from the wellbore is desired at all times during installation of the gravel pack assembly and connection of the production tubing string which normally follows such installation. Accordingly, it is important to be able to control the flow of fluid through the interior of the gravel pack assembly at a predetermined time while otherwise permitting some fluid flow before and during installation of the gravel pack assembly. In this regard the present invention provides an improved and unique fluid loss control apparatus which is adapted to be interposed in the gravel pack assembly, particularly an auger-type gravel assembly, during and upon completion of installation.